How do I find out what the OpenID of my Google account is?
I'd like to log in to join the Stack Overflow community, but the OpenID process is very frustrating for me. I did manage to log in a few weeks ago and I thought I managed to connect to my Google OpenID. But I don't recall the OpenID. The obvious option (my account username) is an email which can't be an OpenID. I can't find any reference to an OpenID when I look through the preferences, etc in my Google account. The OpenID.net site says to get my ID just go to Google and log in (no further hints given).
The whole point of OpenID is that it is simple to use but for me it is the exact opposite. Could Stack Overflow consider an old-fashioned username/password option? Or am I missing something really obvious?
P.S.: The login page has no way to register except by entering an OpenID.